import {
  document,
	window,
	HTMLCanvasElement,
	requestAnimationFrame,
	cancelAnimationFrame,
core,
	Event,
  Event0
} from "dhtml-weixin"
import * as THREE from './three/Three';
import Stats from 'three/addons/libs/stats.module.js';

import { FlyControls } from 'three/addons/controls/FlyControls.js';
import { EffectComposer } from 'three/addons/postprocessing/EffectComposer.js';
import { RenderPass } from 'three/addons/postprocessing/RenderPass.js';
import { FilmPass } from 'three/addons/postprocessing/FilmPass.js';
import { OutputPass } from 'three/addons/postprocessing/OutputPass.js';

var requestId
Page({
  onShareAppMessage(){
    return getApp().onShare()
  },
  onShareTimeline(){
     return {title:"ThreeX 2.0"}
  },
	onUnload() {
		cancelAnimationFrame(requestId, this.canvas)
		this.worker && this.worker.terminate()
if(this.canvas) this.canvas = null
		setTimeout(() => {
			if (this.renderer instanceof THREE.WebGLRenderer) {
				this.renderer.dispose()
				this.renderer.forceContextLoss()
				this.renderer.context = null
				this.renderer.domElement = null
				this.renderer = null
			}
		}, 0)
	},
  webgl_touch(e){
		const web_e = (window.platform=="devtools"?Event:Event0).fix(e)
		this.canvas.dispatchEvent(web_e)
  },
  onLoad() {
		document.createElementAsync("canvas", "webgl2").then(canvas => {
      this.canvas = canvas
      this.body_load(canvas).then()
    })
  },
  async body_load(canvas3d) {
    const radius = 6371;
    const tilt = 0.41;
    const rotationSpeed = 0.02;

    const cloudsScale = 1.005;
    const moonScale = 0.23;

    const MARGIN = 0;
    let SCREEN_HEIGHT = window.innerHeight - MARGIN * 2;
    let SCREEN_WIDTH = window.innerWidth;

    let camera, controls, scene, renderer, stats;
    let geometry, meshPlanet, meshClouds, meshMoon;
    let dirLight;

    let composer;

    const textureLoader = new THREE.TextureLoader();

    let d, dPlanet, dMoon;
    const dMoonVec = new THREE.Vector3();

    const clock = new THREE.Clock();

    init();
    animate();

    function init() {

      camera = new THREE.PerspectiveCamera( 25, SCREEN_WIDTH / SCREEN_HEIGHT, 50, 1e7 );
      camera.position.z = radius * 5;

      scene = new THREE.Scene();
      scene.fog = new THREE.FogExp2( 0x000000, 0.00000025 );

      dirLight = new THREE.DirectionalLight( 0xffffff, 3 );
      dirLight.position.set( - 1, 0, 1 ).normalize();
      scene.add( dirLight );

      const materialNormalMap = new THREE.MeshPhongMaterial( {

        specular: 0x7c7c7c,
        shininess: 15,
        map: textureLoader.load( 'textures/planets/earth_atmos_2048.jpg' ),
        specularMap: textureLoader.load( 'textures/planets/earth_specular_2048.jpg' ),
        normalMap: textureLoader.load( 'textures/planets/earth_normal_2048.jpg' ),

        // y scale is negated to compensate for normal map handedness.
        normalScale: new THREE.Vector2( 0.85, - 0.85 )

      } );
      materialNormalMap.map.colorSpace = THREE.SRGBColorSpace;

      // planet

      geometry = new THREE.SphereGeometry( radius, 100, 50 );

      meshPlanet = new THREE.Mesh( geometry, materialNormalMap );
      meshPlanet.rotation.y = 0;
      meshPlanet.rotation.z = tilt;
      scene.add( meshPlanet );

      // clouds

      const materialClouds = new THREE.MeshLambertMaterial( {

        map: textureLoader.load( 'textures/planets/earth_clouds_1024.png' ),
        transparent: true

      } );
      materialClouds.map.colorSpace = THREE.SRGBColorSpace;

      meshClouds = new THREE.Mesh( geometry, materialClouds );
      meshClouds.scale.set( cloudsScale, cloudsScale, cloudsScale );
      meshClouds.rotation.z = tilt;
      scene.add( meshClouds );

      // moon

      const materialMoon = new THREE.MeshPhongMaterial( {

        map: textureLoader.load( 'textures/planets/moon_1024.jpg' )

      } );
      materialMoon.map.colorSpace = THREE.SRGBColorSpace;

      meshMoon = new THREE.Mesh( geometry, materialMoon );
      meshMoon.position.set( radius * 5, 0, 0 );
      meshMoon.scale.set( moonScale, moonScale, moonScale );
      scene.add( meshMoon );

      // stars

      const r = radius, starsGeometry = [ new THREE.BufferGeometry(), new THREE.BufferGeometry() ];

      const vertices1 = [];
      const vertices2 = [];

      const vertex = new THREE.Vector3();

      for ( let i = 0; i < 250; i ++ ) {

        vertex.x = Math.random() * 2 - 1;
        vertex.y = Math.random() * 2 - 1;
        vertex.z = Math.random() * 2 - 1;
        vertex.multiplyScalar( r );

        vertices1.push( vertex.x, vertex.y, vertex.z );

      }

      for ( let i = 0; i < 1500; i ++ ) {

        vertex.x = Math.random() * 2 - 1;
        vertex.y = Math.random() * 2 - 1;
        vertex.z = Math.random() * 2 - 1;
        vertex.multiplyScalar( r );

        vertices2.push( vertex.x, vertex.y, vertex.z );

      }

      starsGeometry[ 0 ].setAttribute( 'position', new THREE.Float32BufferAttribute( vertices1, 3 ) );
      starsGeometry[ 1 ].setAttribute( 'position', new THREE.Float32BufferAttribute( vertices2, 3 ) );

      const starsMaterials = [
        new THREE.PointsMaterial( { color: 0x9c9c9c, size: 2, sizeAttenuation: false } ),
        new THREE.PointsMaterial( { color: 0x9c9c9c, size: 1, sizeAttenuation: false } ),
        new THREE.PointsMaterial( { color: 0x7c7c7c, size: 2, sizeAttenuation: false } ),
        new THREE.PointsMaterial( { color: 0x838383, size: 1, sizeAttenuation: false } ),
        new THREE.PointsMaterial( { color: 0x5a5a5a, size: 2, sizeAttenuation: false } ),
        new THREE.PointsMaterial( { color: 0x5a5a5a, size: 1, sizeAttenuation: false } )
      ];

      for ( let i = 10; i < 30; i ++ ) {

        const stars = new THREE.Points( starsGeometry[ i % 2 ], starsMaterials[ i % 6 ] );

        stars.rotation.x = Math.random() * 6;
        stars.rotation.y = Math.random() * 6;
        stars.rotation.z = Math.random() * 6;
        stars.scale.setScalar( i * 10 );

        stars.matrixAutoUpdate = false;
        stars.updateMatrix();

        scene.add( stars );

      }

      renderer = new THREE.WebGLRenderer( { antialias: true } );
      renderer.setPixelRatio( window.devicePixelRatio );
      renderer.setSize( SCREEN_WIDTH, SCREEN_HEIGHT );
      document.body.appendChild( renderer.domElement );

      //

      controls = new FlyControls( camera, renderer.domElement );

      controls.movementSpeed = 1000;
      controls.domElement = renderer.domElement;
      controls.rollSpeed = Math.PI / 24;
      controls.autoForward = false;
      controls.dragToLook = false;

      //

      stats = new Stats();
      document.body.appendChild( stats.dom );

      window.addEventListener( 'resize', onWindowResize );

      // postprocessing

      const renderModel = new RenderPass( scene, camera );
      const effectFilm = new FilmPass( 0.35 );
      const outputPass = new OutputPass();

      composer = new EffectComposer( renderer );

      composer.addPass( renderModel );
      composer.addPass( effectFilm );
      composer.addPass( outputPass );

    }

    function onWindowResize() {

      SCREEN_HEIGHT = window.innerHeight;
      SCREEN_WIDTH = window.innerWidth;

      camera.aspect = SCREEN_WIDTH / SCREEN_HEIGHT;
      camera.updateProjectionMatrix();

      renderer.setSize( SCREEN_WIDTH, SCREEN_HEIGHT );
      composer.setSize( SCREEN_WIDTH, SCREEN_HEIGHT );

    }

    function animate() {

      requestId = requestAnimationFrame( animate );

      render();
      stats.update();

    }

    function render() {

      // rotate the planet and clouds

      const delta = clock.getDelta();

      meshPlanet.rotation.y += rotationSpeed * delta;
      meshClouds.rotation.y += 1.25 * rotationSpeed * delta;

      // slow down as we approach the surface

      dPlanet = camera.position.length();

      dMoonVec.subVectors( camera.position, meshMoon.position );
      dMoon = dMoonVec.length();

      if ( dMoon < dPlanet ) {

        d = ( dMoon - radius * moonScale * 1.01 );

      } else {

        d = ( dPlanet - radius * 1.01 );

      }

      controls.movementSpeed = 0.33 * d;
      controls.update( delta );

      composer.render( delta );

    }
  }
})